Hot Water Systems — Who's Responsible?

In most townhouse schemes, each lot has its own hot water system — and the owner looks after it. That's a big difference from some apartment buildings where there's a shared centralised system. The practical rule: a system inside your lot that serves only your townhouse is yours; a shared system serving more than one lot is common property.

What we're talking about

Hot water systems in townhouse schemes come in several types:

• Electric storage (the older silver cylinder bolted to a wall)
• Gas storage
• Instant (continuous flow) gas systems
• Heat pumps (an outdoor unit, like a small air conditioner)
• Solar hot water with roof panels and a ground tank

Typical position

Grey areas and common disputes

Replacing the system

When a hot water system fails (and they all do — typical life is 8-15 years), the lot owner usually arranges and pays for replacement. A few things to be aware of:

• If the system is mounted externally on a common-property wall, fixing the bracket back to the wall affects common property — strictly, this needs OC approval.
• If you're upgrading from electric to a heat pump or gas, the new equipment may be bigger, noisier, or in a different location — those changes do need approval — under s110 if it's a minor renovation, otherwise a special resolution under s108.
• If the system was upgraded by a previous owner without approval, you may have inherited an undocumented installation. That's typically not your fault, but you may want to formalise it before the next replacement.

Heat pumps and noise

Heat pump hot water systems have a small compressor that hums when running. In a small townhouse scheme with units close together, that's something to think about — particularly if the unit is going outside a neighbour's bedroom. The approval is the right place to deal with location and any noise mitigation.

Solar hot water

Solar systems usually have panels on the roof (common property) and a tank either at ground level or in the roof space. The system as a whole usually serves one lot, so it's owner-owned. But because the panels sit on common property, installing a new system or replacing one needs approval first — the same as solar PV panels. A by-law can't block sustainability infrastructure such as solar purely on appearance grounds, unless the property is heritage-listed or in a heritage conservation area (s139B).

Roof or wall leaks caused by a hot water system

If the unit bursts and damages common property (e.g. water runs down the wall), the OC repairs the common property and can recover the cost from the lot owner responsible (s132 or s120) — particularly if the unit was old, neglected, or known to be failing. Annual inspections and timely replacement protect everyone.